WHO Drug Information Vol. 24, No. 4, 2010

Consultation DocumentsWHO Drug Information Vol. 24, No. 4, 2010The principal spot obtained with solution A corresponds in position, appearance, andintensity to that obtained with solution B.B. Disperse the quantity of contents of the capsules containing about 50 mg of Emtricitabinewith 40 ml of methanol R, dilute to 50 ml and filter. Dilute 1 ml of the filtrateto 50 ml with methanol R. The absorption spectrum (1.6) of the resulting solution,when observed between 220 and 350 nm, exhibits two maxima at about 242 nm and284 nm.C. See the test described under Assay, Method A. The retention time of the principalpeak in the chromatogram obtained with the test solution is similar to that in thechromatogram obtained with the reference solution.Dissolution. Carry out the test as described under 5.5 Dissolution test for solid oraldosage forms, using as the dissolution medium, 900 ml of hydrochloric acid (~4 g/l) TSand rotating the paddle at 50 revolutions per minute. At 45 minutes withdraw a sampleof 10 ml of the medium through an in-line filter. Allow the filtered sample to cool toroom temperature. Measure the absorbance (1.6) of a 1-cm layer of the resultingsolution, suitably diluted if necessary, at the maximum at about 280 nm. Determine thecontent of emtricitabine (C 8H 10FN 3O 3S) in the medium from the absorbance obtainedfrom a solution of known concentration of emtricitabine RS.For each of the six capsules tested, calculate the total amount of emtricitabine(C 8H 10FN 3O 3S) in the medium from the results obtained and from the declared contentof C 8H 10FN 3O 3S in emtricitabine RS. The amount in solution for each capsule is notless than 80% of the amount declared on the label. If the amount of emtricitabineobtained for one of the six capsules is less than 80%, repeat the test using a furthersix capsules; the average amount of emtricitabine for all 12 capsules tested is not lessthan 75% and no capsule contains less than 60%.Related substancesCarry out the test as described under 1.14.4 High-performance liquid chromatography,using the conditions given under Assay, Method A.Prepare the following solutions using a mixture of 20 volumes of acetonitrile R and 80volumes of water R as a diluent. For solution (1) weigh and mix the contents of 20capsules and disperse a quantity containing about 50 mg of Emtricitabine in 80 ml ofthe diluent, dilute to 100 ml with the diluent, filter and use the filtrate. For solution (2)dilute a suitable volume of solution (1) with the diluent to obtain a concentration of0.50 µg of Emtricitabine per ml.For the system suitability test: prepare solution (3) using 5 ml of solution (1) and 2 mlof phosphoric acid (~105 g/l) TS, heat carefully in a boiling water-bath for 15 minutes.Operate with a flow rate of 1.0 ml per minute. As a detector use an ultraviolet spectrophotometerset at a wavelength of 280 nm.Maintain the column temperature at 35 °C.Inject 20 µl of solution (3). The test is not valid unless the resolution between the peakdue to emtricitabine (retention time about 9 minutes) and the peak with a relativeretention of about 1.3 is not less than 6.328